Crystals have unique properties and often show superior characteristics. Accordingly, various elements using an organic crystal material have been proposed (under the editorship of Hachirou Nakanishi, Yuuki Kesshou Zairyou no Saishin Gijyutsu, CMC Publishing Co., Ltd., Japan, 2005). Meanwhile, various methods for manufacturing an organic semiconductor material have been proposed (see, for example, JP-A-10-190001). Nevertheless, semiconductor elements using a crystal made of an organic semiconductor material have not been studied extensively.
Only recently has a method by which a single crystal of pentacene is formed so as to form a semiconductor element by using a flake of the single crystal been proposed (J. Takeya, “Field induced-Charge Transport at the Surface of Pentacene Single Crystals: A Method to Study Charge Dynamics of Two-Dimensional Electron Systems in Organic Crystals”, Journal of Applied Physics, Vol. 94, page. 5800, 2003). This method, however, has a problem that the mass productivity is poor.
Also, Yamamoto has proposed a method for growing a single crystal of organic molecules on a silicon substrate through a chemical reaction by immersing a silicon substrate incorporating copper or silver electrodes in a solution of dicyanoquinonediimine (Hiroshi M. Yamamoto, “Direct Formation of Micro-/Nanocrystalline 2,5-Dimethyl-N,N-dicyanoquinonediimine Complexes on SiO2/Si substrates and Multiprobe Measurement of Conduction Properties”, Journal of American Chemical Society, Vol. 128, Issue 3, page 700, 2006).
However, as is shown in FIG. 3 of the article by Yamamoto cited above, the method described in the cited article fails to control a position at which a crystal is to be formed. It is therefore difficult to make this method available for industrial applications.